Mechanism of anti-diabetic action, efficacy and safety profile of GII purified from fenugreek (Trigonella foenum-graceum Linn.) seeds in diabetic animals.

Mechanism of action of GII (100 mg/kg body weight, po for 15 days) purified from fenugreek (T. foenum-graecum) seeds was studied in the sub-diabetic and moderately diabetic rabbits. In the sub-diabetic rabbits it did not change much the content of total lipids, glycogen and proteins in the liver, muscle and heart (glycogen was not studied in the heart). However, in the moderately diabetic rabbits same treatment decreased total lipids more in the liver (21%) than those in the heart and muscle. Total protein content increased (14%) in the liver but negligible change (5-7%) was observed in heart and muscle. Glycogen increased (17%) in the liver but not in the muscle of the moderately diabetic rabbits (glycogen was not estimated in the heart). Among the enzymes of glycolysis, activity of glucokinase was not affected in the liver of both the sub-diabetic and moderately diabetic rabbits. Phosphofructokinase and pyruvate kinase activity in both sub-diabetic and moderately diabetic rabbits increased (13-50%) indicating stimulation of glycolysis. The activity of gluconeogenic enzymes glucose-6-phosphatase and fructose-1,6-diphosphatase of the sub-diabetic rabbits decreased in the liver (15-20%) but not in the kidneys. In the moderately diabetic rabbits after treatment with GII, glucokinase in the liver was not affected much (-9%) but increased well in the muscle (40%). Phosphofructokinase and pyruvate kinase were moderately increased both in the liver and the muscle (18-23%). The gluconeogenic enzyme glucose-6-phosphatase decreased reasonably well in the liver and kidneys (22, 32%). Fructose-1,6-diphosphatase decreased only slightly (10, 9%) in the moderately diabetic rabbits. Thus GII seems to decrease lipid content of liver and stimulate the enzymes of glycolysis (except glucokinase) and inhibit enzymes of gluconeogenesis in the liver of the diabetic especially moderately diabetic rabbits.

Anti-hyperglycemic compound (GII) from fenugreek (Trigonella foenum-graecum Linn.) seeds, its purification and effect in diabetes mellitus.

An anti-hyperglycemic compound named GII was purified from the water extract of the seeds of fenugreek (T. foenum-graecum) and shown to be different from trigonelline and nicotinic acid isolated earlier from the same plant. GII (50 mg/kg body weight, po) reduced blood glucose in glucose tolerance test (GTT) in the sub-diabetic and moderately diabetic rabbits and significantly reduced the area under the curve (AUC) of GTT. Treatment for 7 days of the sub-diabetic rabbits with GII (50 mg/kg body weight, po) improved glucose tolerance without reducing fasting blood glucose (FBG) which was nearly normal. The results suggest that there is no risk of hypoglycemia in near normal animals (may be humans also) with abnormal GTT. Treatment of the moderately diabetic rabbits with GII (100 mg/kg body weight for 3 weeks) reduced FBG to nearly normal value and improved GTT. GII was more effective than the standard drug tolbutamide. Intermittent therapy given on days 1–5, 11–15, 26–30 and 56–60 to moderately diabetic rabbits leaving in between days without treatment brought down FBG to normal and AUC during GTT was normal. After 15 days treatment with GII (100 mg/kg body weight for 3 weeks) glycosylated hemoglobin came down and insulin increased to normal values in the sub-diabetic, moderately diabetic and severely diabetic rabbits. GII treatment (100 mg/kg body weight for 15 days) brought down all the altered serum lipids (TC, HDLC, TAG, PLs and FFAs) to normal levels. The results suggest that intermittent therapy, instead of daily therapy is possible and GII has good potential as an oral anti-diabetic drug with intermittent therapy.

Coronary risk variables in young asymptomatic smokers.

BACKGROUND AND OBJECTIVES: Smoking plays a dominant role in premature atherosclerosis particularly among males in South Asian countries. It initiates and promotes atherosclerosis by altering cardiac haemodynamics, causing dyslipidaemia and producing oxidative damage. Not much information is available from our country. We therefore undertook this study to see the effect of smoking on electrocardiogram (ECG), blood pressure, lipids, apolipoprotein B level and free radical activity in young asymptomatic male smokers. METHODS: The study included 100 consecutive male subjects (50 smokers and 50 non smokers) aged 30-40 yr. Smoking profile, detailed cardiovascular assessment including ECG and lipid profile were evaluated in each subject. RESULTS: Of the 50 smokers, 22 (44%) had grade I hypertension as against 5 of 50 non smokers. Sinus tachycardia (10%) and P-pulmonale (8%) were the only notable ECG abnormalities. Dyslipidaemia was detected in 92 per cent smokers and 48 per cent non smokers (P<0.001). Total serum cholesterol, low density lipoprotein (LDL)-cholesterol, triglycerides and apolipoprotein B levels were significantly higher (P<0.001) in smokers compared to non smokers. LDL-cholesterol was > or =135 mg/dl in 94 per cent dyslipidaemic smokers. However, no significant difference was found in high density lipoprotein (HDL)-cholesterol. Smokers had significantly higher serum malondialdehyde levels (P<0.001) and low superoxide dismutase (P<0.001) compared to non smokers. INTERPRETATION AND CONCLUSION: Our data indicate that young asymptomatic male smokers tend to have hypertension, dyslipidaemia and increased production of free oxygen radicals, perhaps by attenuation of oxidative stress by cigarette smoking. This makes them prone for premature coronary artery disease. However, the findings need to be confirmed on a larger sample.

Mechanism of action of a hypoglycemic principle isolated from fenugreek seeds.

Mechanism of action of an orally active hypoglycemic principle isolated from water extract of seeds of Trigonella foenum graecum (fenugreek) was investigated in alloxan induced subdiabetic and overtly diabetic rabbits of different severities. The active principle was orally administered to the subdiabetic and mild diabetic rabbits (five in each group) at a dose of 50 mg/kg body weight for 15 days. The treatment produced significant attenuation of the glucose tolerance curve and improvement in the glucose induced insulin response, suggesting that the hypoglycemic effect may be mediated through stimulating insulin synthesis and/or secretion from the beta pancreatic cells of Langerhans. Prolonged administration of the same dose of the active principle for 30 days to the severely diabetic rabbits (n = 5) lowered fasting blood glucose significantly, but could elevate the fasting serum insulin level to a much lower extent, which suggests an extra-pancreatic mode of action for the active principle. The effect may also be by increasing the sensitivity of tissues to available insulin. The hypoglycemic effect was observed to be slow but sustained, without any risk of developing severe hypoglycemia.

Studies on oxidative stress, serum iron and iron binding capacity in subjects prone to the risk of coronary artery disease.

Lipid peroxidation in vitro and in vivo has been postulated to be involved in the development of atherosclerosis. It is also known that free iron catalyses the lipid peroxidation. Therefore, we assessed the status of oxidative stress in smokers, hypertensives and non-insulin dependent subjects, who were prone to coronary artery disease. In addition, superoxide dismutase levels and iron binding capacity were also measured to know their antioxidant defences. One hundred seventy-five consecutive subjects below 60 years of age were examined; they were then divided into three groups: one with coronary artery disease, another without coronary artery disease and a healthy control group. The patients having either of the one risk factors for coronary artery disease i.e. smoking, hypertension and/or diabetes were studied. Serum lipid peroxides, superoxide dismutase, serum iron and iron binding capacity were estimated. Oxidative stress was highest in smokers with coronary artery disease (3.11+/-0.79 mmol/ml) as compared to hypertensives (2.69+/-0.20 mmol/nl) and non-insulin dependent diabetics (2.78+/-0.19 mmol/ml). Superoxide dismutase activity was also significantly decreased (p<0.001) in smokers with coronary artery disease as compared to hypertensives and non-insulin dependent diabetes mellitus. Final step of stepwise logistic regression based on malondialdehyde and superoxide dismutase correctly predicted coronary artery disease status in 90 percent smokers. Serum iron and total iron binding capacity were not significantly different in risk prone subjects. However, among all risk prone subjects, smokers with coronary artery disease showed highest serum iron levels and decreased iron binding capacity.

Lipoprotein(a) as an independent risk factor for coronary artery disease in patients below 40 years of age.

Coronary artery disease has assumed alarming proportions in Indians and often affects people at younger age. Traditional risk factors fail to explain the high incidence of disease. Although lipoprotein(a) has been shown to be a powerful risk factor for atherosclerosis, there is very limited data with regard to its significance in premature coronary artery disease. The present study was therefore undertaken to assess lipoprotein(a) levels and its role as a marker of coronary artery disease in patients below the age of 40 years. Lipid profile and lipoprotein(a) levels were estimated in 50 patients of angiographically proven coronary artery disease and an equal number of age-matched healthy controls. There was no significant difference in the family history of coronary artery disease, body mass index and waist-hip ratio between the two groups. Total plasma cholesterol, triglyceride and LDL-cholesterol levels were significantly higher and HDL-cholesterol significantly lower in patients as compared to controls. In patients of coronary artery disease, mean lipoprotein(a) levels, measured by ELISA method, were 35.0 +/- 32.4 mg/dL and the median was 26.7 mg/dL. These values were significantly higher than the mean of 20.3 +/- 17.0 mg/dL (p < 0.002) and the median of 13.8 mg/dL (p < 0.015) in controls. Multiple regression analysis, to assess the influence of various risk factors, showed that low HDL-cholesterol (odds ratio 4.62, 95% CI 1.84-11.60; p < 0.015) and elevated lipoprotein(a) levels (odds ratio 3.06, 95% CI 1.24-7.55; p < 0.001) were independent risk factors, whereas high total cholesterol and triglyceride levels did not have any independent influence on premature coronary artery disease. Our data thus suggest that lipoprotein (a) levels are elevated and constitute an independent risk factor in patients with premature coronary artery disease below 40 years of age.

Effect of captopril on serum angiotensin converting enzyme and blood pressure in hypertensive patients.

The effect of chronic captopril therapy on serum angiotensin converting enzyme (ACE) was studied in 30 patients with essential hypertension. Patients were assessed for serum ACE levels serially every week for 4 weeks. Thirty healthy individuals served as controls. The basal serum ACE level among hypertensives (57.4 +/- 37.2 u/l) was found to be significantly higher (p < 0.001) than the controls (33.3 +/- 8.8 u/l). One week after starting captopril therapy, serum ACE levels fell to almost half the basal values (p < 0.001). However, thereafter, it rose to levels higher than the basal level even though the blood pressure remained well controlled. Our study suggests that besides its action on ACE, captopril may lower the blood pressure by other mechanisms as well.